Fill DataGrid with DataTable

Here is an example of how to do it, I just tried it.

Event load of the form

       private void Form1_Load(object sender, EventArgs e)
       {
            var dt = new DataTable();
            dt.Columns.Add("Nombre");
            dt.Columns.Add("Edad");
            dt.Columns.Add("Cedula de la persona");

            dt.Rows.Add("Nombre 1",12,"239847893-4565464");
            dt.Rows.Add("Nombre 2", 16, "23se59847893-4565464");


            dataGridView1.AutoSizeColumnsMode = 
            DataGridViewAutoSizeColumnsMode.Fill;

            dataGridView1.DataSource = dt;

       }

The first thing I did was create an example table, and create the structure with the columns.add method of the data table, then add several records with the rows.add method of the data table, to fill the data grid use the property data source of the datagrid and to adjust the column use the AutoSizeColumnsMode property of the data grid and assign it the enumerable DataGridViewAutoSizeColumnsMode with the value fill.

The person's ID column was automatically adjusted, and created with a large size for the test

In case someone has the same problem and needs to do it with a datagrid it is solved like this:

       //cargo el datagrid 
        dataGrid1.ItemsSource = dt.DefaultView;

Now I modify the datagrid:

      double ncolumnas = Convert.ToDouble(dt.Columns.Count);
      double tamlargo = this.dataGrid1.ActualWidth;
    //ajusta el largo de cada columna 
        dataGrid1.ColumnWidth = tamlargo / ncolumnas;
    //quitar scroll 
        dataGrid1.HorizontalScrollBarVisibility= 0;
        dataGrid1.VerticalScrollBarVisibility = 0;
    //quita la que aparece con las flechas ojo no cambiar el header
        dataGrid1.RowHeaderWidth = 0;